Semiconductive rubber belt, and process for producing the same
An object of the present invention is to provide a semiconductive rubber belt wherein a variation in the electric resistance is decreased, in particular, in the belt circumferential direction so that high-quality images can be formed, and a process for producing the same. In order to achieve the object, in a case where on any single straight line extended in the belt circumferential direction, the maximum value of the molecular orientation ratio correction value MOR-C of the semiconductive rubber belt, the minimum value thereof, and the average thereof are set to satisfy a specified relationship.
1. A seamless vulcanized semiconductive rubber belt having a volume resistivity of 10 4 to 10 12 ohm-centimeters (Ωcm),
wherein about the molecular orientation ratio correction value MOR-C of the vulcanized semiconductive rubber belt on any single straight line extended in the belt circumferential direction orthogonal to the width direction of the belt, the molecular orientation ratio correction value being represented by the following expression (1):
MOR−C =(( t c ×( MOR− 1)/ t s )+1 (1)
wherein MOR represents the molecular orientation ratio, t c represents the correction thickness (in millimeters, mm), and t s represents the thickness (mm) of the belt,
the following expressions (2) and (3) are satisfied:
( a−b )/ c< 0.64 (2), and
a/b< 1.87 (3)
wherein a represents the maximum value of the molecular orientation ratio correction value MOR-C, b represents the minimum thereof, and c represents the average.
2. The seamless vulcanized semiconductive rubber belt of claim 1 , wherein a rubber substrate layer of the vulcanized semiconductive rubber belt is made of a rubber material containing at least one of the group consisting of chloroprene rubber, ethylene-propylene rubber and ethylene-propylene-diene rubber, nitrile rubber, and epichlorohydrin rubber and epichlorohydrin-ethylene oxide rubber.